The Biotechnology Unit is responsible for the production and purification of biological material. The Unit undertakes a wide array of biological production tasks such as large-scale growth of prokaryotes and eucaryotes, and production and purification of biological compounds especially proteins. These products, not available from commercial sources, are needed for clinical and structural studies. The Biotechnology Unit is capable of handling these various production tasks by implementing both physiological and technical approaches. Efficient process development and production is possible since the Unit possesses two integrated elements: a fully operational multi-purpose pilot production facility and the capability of conducting research and process development. During the last year the unit performed approximately 200 different, large scale preparations including: 1) growing various microorganisms such as recombinant Escherichia coli, recombinant Saccharomyces cerevisiae, recombinant Pichia pastoris, mutant strains of Corynebacteria diphtheria, several types of Salmonella and Shigella and mutant strain of Bacillus anthracis; 2) propagating large volumes of various eucaryotic cells such as HeLa, CHO, drosophila and Sf-9; 3) purifying gram quantities of diphtheria toxin CRM (Cross Reacting Material) and recombinant Pseudomonas aeruginosa exotoxin A needed for the preparation of conjugated vaccines. In the research and development arena, the unit continues its work in the following topics: 1) development of more efficient methods for large scale protein recovery, here we performed experiments implementing expanded bed adsorption techniques for capturing proteins on ion exchangers, chelating and hydrophobic resins; 2) conducting research aimed at understanding the glucose metabolism of various recombinant E. coli strains in an effort to find out why certain strains are more suitable for foreign protein production using microarrays technology and protein analysis; 3) developing fermentation procedures for expressing sensitive, recombinant clostridium protein from e.coli by suppressing proteolytic activity; and 4) conducting experiments for improving the production protocol of recombinant proteins from Pichia pastoris, especially endostatin. In addition, the unit continues its research work in two topics, one is on the effect of various high density growth strategies of recombinant E.coli, on the production of recombinant proteins, and the other is on the production process of recombinant proteins from the HeLa/vaccinia system. In collaboration with LDMI, NICHD, the unit conducted work on the development of new vaccine against Salmonella typhi, and shigella flexneri. The products are currently in field trials.